demo: include SOCKS proxy support

demo/android/build.gradle

@@ -69,6 +69,7 @@ dependencies {
     implementation "androidx.lifecycle:lifecycle-viewmodel-compose:$lifecycleVersion"
     implementation "androidx.lifecycle:lifecycle-runtime-compose:$lifecycleVersion"
     implementation "androidx.activity:activity-compose:1.6.1"
+    implementation "androidx.datastore:datastore-preferences:1.0.0"
 
     implementation "androidx.room:room-runtime:$roomVersion"
     implementation "androidx.room:room-ktx:$roomVersion"

demo/android/src/main/kotlin/im/molly/monero/demo/AppModule.kt

@@ -3,7 +3,6 @@ package im.molly.monero.demo
 import android.app.Application
 import androidx.room.Room
 import im.molly.monero.demo.data.*
-import okhttp3.OkHttpClient
 
 /**
  * Naive container of global instances.
@@ -11,7 +10,7 @@ import okhttp3.OkHttpClient
  * A complex app should use Koin or Hilt for dependencies.
  */
 object AppModule {
-    lateinit var application: Application
+    private lateinit var application: Application
 
     private val applicationScope = kotlinx.coroutines.MainScope()
 
@@ -21,10 +20,6 @@ object AppModule {
         ).build()
     }
 
-    private val walletHttpClient: OkHttpClient by lazy {
-        OkHttpClient.Builder().build()
-    }
-
     private val walletDataSource: WalletDataSource by lazy {
         WalletDataSource(database.walletDao())
     }
@@ -34,7 +29,11 @@ object AppModule {
     }
 
     private val moneroSdkClient: MoneroSdkClient by lazy {
-        MoneroSdkClient(application, walletDataFileStorage, walletHttpClient)
+        MoneroSdkClient(application, walletDataFileStorage)
+    }
+
+    val settingsRepository: SettingsRepository by lazy {
+        SettingsRepository(application.preferencesDataStore)
     }
 
     val remoteNodeRepository: RemoteNodeRepository by lazy {
@@ -42,7 +41,7 @@ object AppModule {
     }
 
     val walletRepository: WalletRepository by lazy {
-        WalletRepository(moneroSdkClient, walletDataSource, applicationScope)
+        WalletRepository(moneroSdkClient, walletDataSource, settingsRepository, applicationScope)
     }
 
     fun provide(application: Application) {

demo/android/src/main/kotlin/im/molly/monero/demo/MainActivity.kt

@@ -6,8 +6,6 @@ import android.content.Intent
 import android.content.ServiceConnection
 import android.os.Bundle
 import android.os.IBinder
-import android.os.StrictMode
-import android.os.StrictMode.VmPolicy
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.compose.foundation.isSystemInDarkTheme

demo/android/src/main/kotlin/im/molly/monero/demo/MainApplication.kt

@@ -1,10 +1,16 @@
 package im.molly.monero.demo
 
 import android.app.Application
+import android.content.Context
 import android.os.StrictMode
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.preferencesDataStore
 import im.molly.monero.demo.service.SyncService
 import im.molly.monero.isIsolatedProcess
 
+val Context.preferencesDataStore: DataStore<Preferences> by preferencesDataStore(name = "settings")
+
 class MainApplication : Application() {
 
     override fun onCreate() {

demo/android/src/main/kotlin/im/molly/monero/demo/data/MoneroSdkClient.kt

@@ -10,7 +10,6 @@ import okhttp3.OkHttpClient
 class MoneroSdkClient(
     private val context: Context,
     private val walletDataFileStorage: WalletDataFileStorage,
-    private val httpClient: OkHttpClient,
     private val ioDispatcher: CoroutineDispatcher = Dispatchers.IO,
 ) {
     private val providerDeferred = CoroutineScope(ioDispatcher).async {
@@ -31,6 +30,7 @@ class MoneroSdkClient(
     suspend fun openWallet(
         publicAddress: String,
         remoteNodes: Flow<List<RemoteNode>>,
+        httpClient: OkHttpClient,
     ): MoneroWallet {
         val provider = providerDeferred.await()
         return withContext(ioDispatcher) {

demo/android/src/main/kotlin/im/molly/monero/demo/data/WalletRepository.kt

@@ -4,19 +4,27 @@ import im.molly.monero.*
 import im.molly.monero.demo.data.model.WalletConfig
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
+import okhttp3.OkHttpClient
 import java.util.concurrent.ConcurrentHashMap
 
 class WalletRepository(
     private val moneroSdkClient: MoneroSdkClient,
     private val walletDataSource: WalletDataSource,
+    private val settingsRepository: SettingsRepository,
     private val externalScope: CoroutineScope,
 ) {
     private val walletIdMap = ConcurrentHashMap<Long, Deferred<MoneroWallet>>()
 
+    private val sharedHttpClient = OkHttpClient.Builder().build()
+
     suspend fun getWallet(walletId: Long): MoneroWallet {
         return walletIdMap.computeIfAbsent(walletId) {
             externalScope.async {
                 val config = getWalletConfig(walletId)
+                val userSettings = settingsRepository.getUserSettings().first()
+                val httpClient = sharedHttpClient.newBuilder()
+                    .proxy(userSettings.activeProxy)
+                    .build()
                 val wallet = moneroSdkClient.openWallet(
                     publicAddress = config.first().publicAddress,
                     remoteNodes = config.map {
@@ -27,7 +35,8 @@ class WalletRepository(
                                 password = node.password,
                             )
                         }
-                    }
+                    },
+                    httpClient = httpClient,
                 )
                 wallet
             }
@@ -36,6 +45,9 @@ class WalletRepository(
 
     fun getWalletIdList() = walletDataSource.readWalletIdList()
 
+    fun getRemoteClients(): Flow<List<RemoteNodeClient>> =
+        getWalletIdList().map { it.mapNotNull { walletId -> getWallet(walletId).remoteNodeClient } }
+
     fun getWalletConfig(walletId: Long) = walletDataSource.readWalletConfig(walletId)
 
     fun getLedger(walletId: Long): Flow<Ledger> = flow {

demo/android/src/main/kotlin/im/molly/monero/demo/ui/SettingsScreen.kt

@@ -1,13 +1,12 @@
 package im.molly.monero.demo.ui
 
 import android.net.Uri
-import androidx.annotation.StringRes
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material3.*
-import androidx.compose.runtime.Composable
+import androidx.compose.runtime.*
-import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
@@ -15,8 +14,9 @@ import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
-import im.molly.monero.demo.R
 import im.molly.monero.demo.data.model.RemoteNode
+import im.molly.monero.demo.data.model.UserSettings
+import im.molly.monero.demo.data.model.toSocketAddress
 import im.molly.monero.demo.ui.theme.AppIcons
 import im.molly.monero.demo.ui.theme.AppTheme
 
@@ -26,46 +26,72 @@ fun SettingsRoute(
     viewModel: SettingsViewModel = viewModel(),
     navigateToEditRemoteNode: (Long?) -> Unit,
 ) {
-    val remoteNodes by viewModel.remoteNodes.collectAsStateWithLifecycle()
+    val settingsUiState by viewModel.settingsUiState.collectAsStateWithLifecycle()
 
     SettingsScreen(
-        remoteNodes = remoteNodes,
+        settingsUiState = settingsUiState,
         modifier = modifier,
         onAddRemoteNode = { navigateToEditRemoteNode(RemoteNode.EMPTY.id) },
         onEditRemoteNode = { navigateToEditRemoteNode(it.id) },
         onDeleteRemoteNode = { viewModel.forgetRemoteNodeDetails(it) },
+        onChangeSocksProxy = { viewModel.setSocksProxyAddress(it) },
+        onValidateSocksProxy = { viewModel.isSocksProxyAddressCorrect(it) },
     )
 }
 
 @Composable
 private fun SettingsScreen(
-    remoteNodes: List<RemoteNode>,
+    settingsUiState: SettingsUiState,
     modifier: Modifier = Modifier,
     onAddRemoteNode: () -> Unit = {},
     onEditRemoteNode: (RemoteNode) -> Unit = {},
     onDeleteRemoteNode: (RemoteNode) -> Unit = {},
+    onChangeSocksProxy: (String) -> Unit = {},
+    onValidateSocksProxy: (String) -> Boolean = { true },
 ) {
     Column(
         modifier = modifier
             .verticalScroll(rememberScrollState())
     ) {
-        SettingsSection(
+        when (settingsUiState) {
-            header = {
+            SettingsUiState.Loading -> {
-                SettingsSectionTitle(R.string.remote_nodes)
+                // TODO: Add loading wheel
-                IconButton(onClick = onAddRemoteNode) {
+            }
-                    Icon(
+            is SettingsUiState.Success -> {
-                        imageVector = AppIcons.AddRemoteWallet,
+                SettingsSection(
-                        contentDescription = stringResource(R.string.add_remote_node),
+                    header = {
+                        SettingsSectionTitle("Remote nodes")
+                        IconButton(onClick = onAddRemoteNode) {
+                            Icon(
+                                imageVector = AppIcons.AddRemoteWallet,
+                                contentDescription = "Add remote node",
+                            )
+                        }
+                    }
+                )
+                RemoteNodeEditableList(
+                    remoteNodes = settingsUiState.remoteNodes,
+                    onEditRemoteNode = onEditRemoteNode,
+                    onDeleteRemoteNode = onDeleteRemoteNode,
+                    modifier = Modifier.padding(start = 24.dp),
+                )
+                SettingsSection(
+                    header = {
+                        SettingsSectionTitle("Network")
+                    }
+                ) {
+                    EditTextSettingsItem(
+                        title = "SOCKS proxy server",
+                        summary = "Connect via proxy.",
+                        value = settingsUiState.socksProxyAddress,
+                        onValueChange = onChangeSocksProxy,
+                        inputHeading = "Provide proxy address or leave it blank for no proxy.",
+                        inputLabel = "host:port",
+                        inputChecker = onValidateSocksProxy,
                     )
                 }
             }
-        )
+        }
-        RemoteNodeEditableList(
-            remoteNodes = remoteNodes,
-            onEditRemoteNode = onEditRemoteNode,
-            onDeleteRemoteNode = onDeleteRemoteNode,
-            modifier = Modifier.padding(start = 24.dp),
-        )
     }
 }
 
@@ -78,7 +104,7 @@ private fun SettingsSection(
     Column(
         modifier = modifier.padding(horizontal = 24.dp),
     ) {
-        Divider(Modifier.padding(top = 24.dp))
+        Divider(Modifier.padding(bottom = 24.dp))
         Row(
             horizontalArrangement = Arrangement.SpaceBetween,
             verticalAlignment = Alignment.CenterVertically,
@@ -92,20 +118,86 @@ private fun SettingsSection(
 }
 
 @Composable
-private fun SettingsSectionTitle(@StringRes titleRes: Int) {
+private fun SettingsSectionTitle(title: String) {
     Text(
-        text = stringResource(titleRes),
+        text = title,
         style = MaterialTheme.typography.titleMedium,
+        modifier = Modifier.padding(vertical = 8.dp),
     )
 }
 
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun EditTextSettingsItem(
+    title: String,
+    summary: String,
+    value: String,
+    onValueChange: (String) -> Unit,
+    inputLabel: String,
+    inputHeading: String = title,
+    inputChecker: (String) -> Boolean = { true },
+) {
+    var showDialog by remember { mutableStateOf(false) }
+
+    ListItem(
+        headlineText = { Text(title) },
+        supportingText = { Text(summary) },
+        trailingContent = { Text(value) },
+        modifier = Modifier
+            .clickable(onClick = { showDialog = true }),
+    )
+
+    if (showDialog) {
+        var input by remember { mutableStateOf(value) }
+        val valid = inputChecker(input)
+
+        AlertDialog(
+            text = {
+                Column {
+                    Text(
+                        text = inputHeading,
+                        modifier = Modifier.padding(vertical = 16.dp),
+                    )
+                    OutlinedTextField(
+                        label = { Text(inputLabel) },
+                        value = input,
+                        onValueChange = { input = it },
+                        singleLine = true,
+                        isError = !valid,
+                    )
+                }
+            },
+            onDismissRequest = { showDialog = false },
+            dismissButton = {
+                TextButton(onClick = { showDialog = false }) {
+                    Text(stringResource(android.R.string.cancel))
+                }
+            },
+            confirmButton = {
+                TextButton(
+                    enabled = valid,
+                    onClick = {
+                        onValueChange(input)
+                        showDialog = false
+                    },
+                ) {
+                    Text(stringResource(android.R.string.ok))
+                }
+            },
+        )
+    }
+}
+
 @Preview
 @Composable
-private fun SettingsScreenPreview() {
+private fun SettingsScreenPopulatedPreview() {
     AppTheme {
         val aNode = RemoteNode.EMPTY.copy(uri = Uri.parse("http://node.monero"))
         SettingsScreen(
-            remoteNodes = listOf(aNode),
+            SettingsUiState.Success(
+                socksProxyAddress = "localhost:9050",
+                remoteNodes = listOf(aNode),
+            )
         )
     }
 }

demo/android/src/main/kotlin/im/molly/monero/demo/ui/SettingsViewModel.kt

@@ -3,29 +3,44 @@ package im.molly.monero.demo.ui
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import im.molly.monero.demo.AppModule
+
 import im.molly.monero.demo.data.RemoteNodeRepository
+import im.molly.monero.demo.data.SettingsRepository
+import im.molly.monero.demo.data.WalletRepository
 import im.molly.monero.demo.data.model.RemoteNode
+import im.molly.monero.demo.data.model.SocksProxy
+import im.molly.monero.demo.data.model.toSocketAddress
 import kotlinx.coroutines.flow.*
 import kotlinx.coroutines.launch
+import java.net.Proxy
 
 class SettingsViewModel(
+    private val settingsRepository: SettingsRepository = AppModule.settingsRepository,
     private val remoteNodeRepository: RemoteNodeRepository = AppModule.remoteNodeRepository,
+    private val walletRepository: WalletRepository = AppModule.walletRepository,
 ) : ViewModel() {
 
-    val remoteNodes: StateFlow<List<RemoteNode>> =
+    val settingsUiState: StateFlow<SettingsUiState> =
-        remoteNodeRepository.getAllRemoteNodes()
+        combine(
-            .stateIn(
+            settingsRepository.getUserSettings(),
-                scope = viewModelScope,
+            remoteNodeRepository.getAllRemoteNodes(),
-                started = SharingStarted.WhileSubscribed(5000),
+            ::Pair,
-                initialValue = listOf(RemoteNode.EMPTY),
+        ).map {
+            SettingsUiState.Success(
+                socksProxyAddress = it.first.socksProxy?.address()?.toString().orEmpty(),
+                remoteNodes = it.second,
             )
+        }.stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000),
+            initialValue = SettingsUiState.Loading,
+        )
 
     fun remoteNode(remoteNodeId: Long): Flow<RemoteNode> =
         remoteNodeRepository.getRemoteNode(remoteNodeId)
 
-    fun isRemoteNodeCorrect(remoteNode: RemoteNode): Boolean {
+    fun isRemoteNodeCorrect(remoteNode: RemoteNode): Boolean =
-        return remoteNode.uri.host?.isEmpty() == false
+        remoteNode.uri.host?.isEmpty() == false
-    }
 
     fun saveRemoteNodeDetails(remoteNode: RemoteNode) {
         viewModelScope.launch {
@@ -38,4 +53,50 @@ class SettingsViewModel(
             remoteNodeRepository.deleteRemoteNode(remoteNode)
         }
     }
+
+    fun isSocksProxyAddressCorrect(address: String) =
+        try {
+            if (address.isNotEmpty()) address.toSocketAddress()
+            true
+        } catch (_: IllegalArgumentException) {
+            false
+        }
+
+    fun setSocksProxyAddress(address: String) {
+        viewModelScope.launch {
+            val socksProxy =
+                if (address.isNotEmpty()) SocksProxy(address.toSocketAddress()) else null
+            settingsRepository.setSocksProxy(socksProxy)
+        }
+    }
+
+    init {
+        // Consider using a ProxySelector in OkHttpClient instead once this bug is resolved:
+        // https://github.com/square/okhttp/issues/7698
+        viewModelScope.launch {
+            settingsRepository.getUserSettings()
+                .distinctUntilChangedBy { it.activeProxy }
+                .map { it.activeProxy }
+                .collect { onProxyChanged(it) }
+        }
+    }
+
+    private suspend fun onProxyChanged(newProxy: Proxy) {
+        walletRepository.getRemoteClients().first().forEach {
+            val currentProxy = it.httpClient.proxy()
+            if (currentProxy != newProxy) {
+                val builder = it.httpClient.newBuilder()
+                it.httpClient = builder.proxy(newProxy).build()
+            }
+        }
+    }
+}
+
+sealed interface SettingsUiState {
+    data class Success(
+        val socksProxyAddress: String,
+        val remoteNodes: List<RemoteNode>,
+    ) : SettingsUiState
+
+    object Loading : SettingsUiState
 }

lib/android/src/main/kotlin/im/molly/monero/MoneroWallet.kt

@@ -9,7 +9,7 @@ import kotlinx.coroutines.suspendCancellableCoroutine
 
 class MoneroWallet internal constructor(
     private val wallet: IWallet,
-    client: RemoteNodeClient?,
+    val remoteNodeClient: RemoteNodeClient?,
 ) : IWallet by wallet, AutoCloseable {
 
     val publicAddress: String = wallet.primaryAccountAddress

lib/android/src/main/kotlin/im/molly/monero/RemoteNodeClient.kt

@@ -19,7 +19,7 @@ class RemoteNodeClient private constructor(
     val network: MoneroNetwork,
     private val loadBalancer: LoadBalancer,
     private val loadBalancerRule: Rule,
-    private val httpClient: OkHttpClient,
+    var httpClient: OkHttpClient,
     private val retryBackoff: BackoffPolicy,
     private val requestsScope: CoroutineScope,
 ) : IRemoteNodeClient.Stub(), AutoCloseable {